1. Field of the Invention
The present invention relates to a turbo code system, more specifically, a turbo code system utilizing cooperative coding architecture and a proper decoding scheduling to achieve high performance real-time encoding and coding.
2. Description of Related Art
Turbo Code (TC) was invented in 1993, which renders extraordinary, near Shannon limit performance by applying the iterative decoding algorithm. Following researches on the area of Forward Error-Control (FEC) were inspired from this primitive code structure and decoding algorithm. We shall thus refer to any FEC system that utilizes the principle of turbo code in decoding as a Turbo Code System (TCS).
Codeword length influences the performance of TCS. TCS with long codeword length performs excellently but decoder of the TCS has large decoding latency and hardware complexity. Moreover, the decoder requires considerable number of iterations to achieve desired performance. The TCS with moderate codeword length often gives unsatisfactory performance. The TCS with short codeword length (say <200) often only provides performance worse than that of conventional coding schemes.
Therefore, the conventional TCS renders high complexity, long decoding latency and large memory space consumption; thereby diminishing their applicability. Commercial FEC applications require affordable complexity, low decoding latency and low power consumption. Furthermore, for use in a future generation wireless communication system, it is preferred that any new enhancement be backward compatible with current air interface standard. It will be shown in the following that the present invention does satisfy all these requirements.